Page 2 - About Your Computer; Front View
Back to Contents Page About Your Computer Dell™ Dimension™ C521 Service Manual Front View Back View of the Computer Back Panel I/O Connectors Front View 1 cover release latch Use this latch to remove the cover. See Removing the Computer Cover . 2 Service Tag Use to identify your compute...
Page 5 - Before You Begin; Getting Started; Recommended Tools; Before Working Inside Your Computer
Back to Contents Page Before You Begin Dell™ Dimension™ C521 Service Manual Getting Started Recommended Tools Turning Off Your Computer Before Working Inside Your Computer Getting Started This manual provides procedures for removing and replacing the components in your computer. Unle...
Page 7 - Replacing the Computer Cover
Back to Contents Page Replacing the Computer Cover Dell™ Dimension™ C521 Service Manual 1. Ensure that all cables are connected, and fold cables out of the way. Gently pull the power cables toward you so that they do not get caught underneath the drives. 2. Ensure that no tools or extra part...
Page 8 - Removing the Computer Cover
Back to Contents Page Removing the Computer Cover Dell™ Dimension™ C521 Service Manual 1. Follow the procedures in Before You Begin . 2. If you have installed a padlock through the padlock ring on the back panel, remove the padlock. 3. Locate the cover release latch shown in the illustra...
Page 9 - Removing and Installing Parts; Memory; DDR2 Memory Overview
Back to Contents Page Removing and Installing Parts Dell™ Dimension™ C521 Service Manual Memory If your computer only has one memory module installed on the system board, you can increase your computer memory by installing an additional memory module. Your computer supports DDR2 memory. For addi...
Page 10 - Installing Memory
Installing Memory 1. Follow the procedures in Before You Begin . 2. Press out the securing clip at each end of the memory module connector. 3. Align the notch on the bottom of the module with the crossbar in the connector. 4. Insert the module into the connector until the module snaps in...
Page 11 - Removing Memory; Cards
7. When a message appears stating that memory size has changed, press <F1> to continue. 8. Log on to your computer. 9. Right-click the My Computer icon, then click Properties . 10. Click the General tab. 11. To verify that the memory is installed correctly, check the amount of memory...
Page 12 - Installing an Expansion Card
Installing an Expansion Card 1. Follow the procedures in Before You Begin . 2. Gently push the release tab on the inside of the card retention door to pivot the door open. Because the door is captive, it will remain in the open position. 3. If you are installing a new card, remove the filler b...
Page 14 - Drives
6. If you are removing the card permanently, install a filler bracket in the empty card-slot opening. 7. Before you close the card retention door, ensure that: l The tops of all cards and filler brackets are flush with the alignment bar. l The notch in the top of the card or filler bracket f...
Page 15 - General Installation Guidelines; Connecting Drive Cables; Drive Interface Connectors
General Installation Guidelines Connect the SATA hard drive to the connector labeled "SATA0." Connect the SATA CD or DVD drives to the connector labeled "SATA1" on the system board. Connecting Drive Cables When you install a drive, you connect two cables — a DC power cable and a ...
Page 16 - Removing a CD/DVD Drive; Installing a CD/DVD Drive
CD/DVD Drive Removing a CD/DVD Drive 1. Follow the procedures in Before You Begin . 2. Pull up on the drive release latch and slide the drive towards the back of the computer. Then, lift up to remove the drive from the computer. 3. Disconnect the power and data cables from the back of ...
Page 17 - Floppy Drive; Removing a Floppy Drive
b. Remove the three shoulder screws from the drive-panel insert. 4. If you are replacing an existing drive: a. Remove the existing drive. b. Remove the three shoulder screws from the existing drive. 5. Insert the three shoulder screws into the sides of the new drive and tighten them. 6. ...
Page 18 - Installing a Floppy Drive
4. Disconnect the power and data cables from the back of the floppy drive. 5. Replace the computer cover. See Replacing the Computer Cover . 6. Connect your computer and devices to electrical outlets, and turn them on. Installing a Floppy Drive 1. Follow the procedures in Before You Begi...
Page 19 - Media Card Reader; Removing a Media Card Reader
8. Slide the drive into the bay until it clicks into place. 9. Connect the data cable to the connector labeled "FLOPPY" on the system board. 10. Replace the CD/DVD drive. 11. Check all cable connections, and fold cables out of the way to provide airflow for the fan and cooling vents....
Page 20 - Installing a Media Card Reader
5. Replace the computer cover. See Replacing the Computer Cover . 6. Connect your computer and devices to electrical outlets, and then turn them on. Installing a Media Card Reader 1. Follow the procedures in Before You Begin . 2. Remove the Media Card Reader and bracket from its packagin...
Page 21 - Hard Drive; Removing a Hard Drive
7. Slide the Media Card Reader into the bay until it clicks into place. 8. Connect the power and data cables to the back of the Media Card Reader. 9. Connect the data cable to the USB connector on the system board. 10. Replace the computer cover. See Replacing the Computer Cover . 11. Conn...
Page 22 - Installing a Hard Drive
Installing a Hard Drive 1. Check the documentation for the drive to verify that it is configured for your computer. 2. Unpack the replacement hard drive, and prepare it for installation. 3. If your replacement hard drive does not have the plastic hard-drive bracket attached, remove the brack...
Page 23 - Battery; Replacing the Battery
7. Gently slide the drive into the bay until it clicks into place. 8. Replace any drives or readers that you removed. 9. Check all connectors to ensure that they are properly cabled and firmly seated. 10. Replace the computer cover. See Replacing the Computer Cover . 11. Connect your compu...
Page 24 - Processor; Removing the Processor
To replace the battery: 1. Record all of the settings in system setup (see System Setup Options ) so that you can restore the correct settings in step 8 . 2. Follow the procedures in Before You Begin . 3. Locate the battery socket. 4. Remove the battery by carefully pressing the battery rele...
Page 25 - Installing the Processor
4. Pull the release lever straight up until the processor is released. 5. Remove the processor from the socket. Leave the release lever extended in the release position so that the socket is ready for the new processor, and go to Installing the Processor . Installing the Processor 1. Follow ...
Page 27 - Power Supply; Replacing the Power Supply
10. Replace the computer cover. See Replacing the Computer Cover . 11. Connect your computer and devices to electrical outlets, and turn them on. Power Supply Replacing the Power Supply 1. Follow the procedures in Before You Begin . 2. Disconnect the DC power cables from the system boa...
Page 28 - Removing the Front I/O Panel
5. Slide the power supply toward the front of the computer and lift the power supply up and out of the computer. 6. Lower the replacement power supply into the computer. 7. Slide the replacement power supply toward the back of the computer until it snaps into place. 8. Replace the screws tha...
Page 29 - Installing the Front I/O Panel; Fan Assembly; Removing the Fan Assembly
6. Disconnect the cable attached to the front I/O panel. 7. Remove the screw that secures the front I/O panel to the chassis. 8. Rotate the I/O panel toward the back of the computer and remove and the I/O panel from the computer. Installing the Front I/O Panel 1. Align the I/O panel connec...
Page 30 - Installing the Fan Assembly; System Board; Removing the System Board
4. Disconnect the fan power cable from the FAN_CPU1 connector on the system board. See System Board Components. 5. While pressing the fan release lever, rotate the fan assembly toward the back of the computer and up to release the two fan tabs from the vent holes in the chassis. 6. Remove the ...
Page 31 - Replacing the System Board
5. Remove the memory. See Removing Memory . Make a note of where each memory module(s) is installed so that you can reinstall the memory module(s) in the same connector. 6. Remove the processor and heat sink assembly. See Removing the Processor . 7. Remove the fan assemble. See Removing the Fa...
Page 33 - Specifications
Back to Contents Page Specifications Dell™ Dimension™ C521 Service Manual Microprocessor Microprocessor type AMD™ Athlon™ 64 X2 Dual -Core processor AMD Athlon 64 AMD Sempron™ Internal L2 cache up to 1 MB per core up to 256 KB for Sempron Memory Type 533-MHz, 667-MHz, 800-MHz z (when available...
Page 36 - System Setup; Overview; Overview; Entering System Setup; System Setup Screen
Back to Contents Page System Setup Dell™ Dimension™ C521 Service Manual Overview Clearing Forgotten Passwords and CMOS Settings Flashing the BIOS Overview Overview Use system setup as follows: l To change the system configuration information after you add, change, or remove any hard...
Page 39 - Boot Menu; Option Settings; Changing Boot Sequence for Future Boots
Boot Menu This feature allows you to change the boot sequence for devices. Option Settings l Bootable Hard Drive — The computer attempts to boot from the primary hard drive. If no operating system is on the drive, the computer generates an error message. l Onboard Floppy Drive — The computer...
Page 40 - Clearing Forgotten Passwords and CMOS Settings; Jumper Locations
1. Enter system setup, select Boot Sequence from the System group. See System Setup Options . 2. Press <Enter> to access the menu. 3. Press the up- and down-arrow keys to highlight the appropriate Boot Sequence option. 4. Press the U or D key to move the option up or down in the boot s...
Page 41 - Clearing CMOS Settings; Flashing the BIOS
Clearing CMOS Settings 1. Follow the procedures in Before You Begin . 2. Reset the current CMOS settings: a. Locate the 2-pin CMOS jumper (RTCRST) on the system board. See Jumper Locations . b. Remove the jumper plug from pin 1. c. Place the jumper plug on pins 1 and 2 and wait approxi...
Page 42 - Technical Overview; Inside View of Your Computer
Back to Contents Page Technical Overview Dell™ Dimension™ C521 Service Manual Inside View of Your Computer System Board Components Power Supply DC Connector Pin Assignments Inside View of Your Computer System Board Components CAUTION: Before you begin any of the procedures in this...
Page 43 - Jumper Settings
Jumper Settings The jumper locations are shown below. 1 fan connector (FAN_CPU1) 2 processor socket (CPU) 3 memory module connectors (DIMM_1, DIMM_2, DIMM_3, DIMM_4) 4 power connector (PW_12V_A1) 5 power connector (POWER1) 6 SATA drive connectors (SATA0, SATA1) 7 front-panel connector (FRONTPANEL)...
Page 44 - Power Supply DC Connector Pin Assignments; DC Power Connector P1
- Power Supply DC Connector Pin Assignments DC Power Connector P1 The real-time clock is being reset (jumpered temporarily). jumpered unjumpered Pin Number Signal name 1 8-AWG Wire 1 +3.3 VDC O r a n g e 2 +3.3 VDC O r a n g e 3 GND Black 4 VCC (+5 V) Red 5 GND Black 6 VCC (+5 V)...
Page 48 - Troubleshooting; When to Use the Dell Diagnostics
Back to Contents Page Troubleshooting Dell™ Dimension™ C521 Service Manual Dell Diagnostics System Lights Diagnostic Lights Beep Codes Dell Diagnostics When to Use the Dell Diagnostics If you experience a problem with your computer, perform the checks in this section and run the ...
Page 50 - Beep Codes
Beep Codes Your computer might emit a series of beeps during start-up if the monitor cannot display errors or problems. This series of beeps, called a beep code, identifies a problem. One possible beep code consists of one long beep and then two short beeps. This beep code tells you that the compu...